1. Field of the Invention
The present invention relates to toner capable of developing a latent image, a toner conveying apparatus, and an image forming apparatus utilizing such toner.
2. Discussion of the Background
It is known that an image forming apparatus employs and conveys toner from a toner container to a prescribed position in the image forming apparatus. Such an image forming apparatus employs an electrophotographic system including a toner container containing replenishing toner, and conveys toner to a developing device. The toner conveyed to the developing device develops a latent image formed on a latent image carrier such as a drum shaped photoconductive member, etc. Another type of an image forming apparatus includes a toner recovery container for containing toner recovered by a cleaning device from a latent image carrier after a toner image has been transferred, and conveys the toner to a discarding toner vessel and the developing device.
In such image forming apparatuses, the toner is conveyed in various manners. For example, the toner is moved and conveyed inside a conveyance pipe connecting a conveyance source to its destination by rotating a coil screw arranged therein.
A toner conveyance destination is located right under a conveyance source so as to drop and convey toner by gravity. Still another image forming apparatus sucks and conveys toner stored in a toner container using a suction pump.
Among these apparatuses, the image forming apparatus conveying the toner by rotating the coil screw has a low degree of a layout freedom, because the conveyance pipe housing the coil screw and a toner conveyance path have to be straight. Further, the image forming apparatus dropping and conveying the toner by gravity has also a low degree of a layout freedom, because the conveyance destination is located right under the conveyance source.
The image forming apparatus that conveys toner by the suction pump does not have to house a conveyance member such as a coil screw in a suction pipe, which connects a suction inlet of the suction pump to a toner container, or an ejection pipe, which connects an ejection outlet of the suction pump to a conveyance destination. Thus, flexible pipes may be used for the suction and ejection pipes and thereby the toner conveyance path is freely designed.
However, depending upon a shape of a toner container, toner adhered to an inner surface of the toner container coalesces with ambient toner and forms a lump, thereby generating the so-called toner blocking phenomenon. As a result, the toner occasionally does not flow into the suction pipe. Then, a type of an image forming apparatus enabling a suction pipe to suck toner and supply air at same time enters the field. According to this type, because the toner in the toner container is stirred and the toner blocking is accordingly disrupted by air pressure and flow caused by the air supply, the toner in the toner container can arrive at the suction pipe. However, toner also clogs in this type of apparatus.
Specifically, according to the type performing the toner suction and air supply at same time, the suction pump operates before the air supplied by the air pump is sufficiently filled in the toner container. Thus, stirring of toner in the toner container is significantly inefficient. Accordingly, the toner suction and air supply occurs at different times.
However, when an air pump is only operated for the purpose of supplying air independently, an inner pressure of the suction pipe is affected and increased by the air supply, thereby promoting coagulation and introducing toner clogging therein.